The present invention relates to a counter plate and a cutting die for use in a die cutting machine, where the counter plate is a receiving surface for cutting blades of the machine while the cutting die is provided for stamping a sheet-shaped material into a predetermined shape.
Heretofore, die cutting machines have been used for stamping a sheet shaped material such as a synthetic resin film, a thin sheet of paper, and a sheet of carton board into a stamped piece thereof having a predetermined shape. The conventional die cutting machine comprises a cutting die and a female die, by which a sheet shaped material is stamped into a predetermined shape by pressing the cutting die against the material placed on the female die.
Conventional die cutting machines typically comprise a cutting die having cutting blades and rulings, and a counter plate or female die. Typically, the counter plate is made of a veneer plate or a metal plate, on which grooves are formed by means of a laser machining, the grooves being adapted to permit insertion of the blades and rulings. Both the cutting blades and the rulings are typically formed by bending a strip of plate material and inserting it into the grooves formed on the base plate. The counter plate or receiving plate is arranged opposite the cutting die in the die cutting machine. The counter plate is usually made of a metal plate with a thickness of about 1.5 mm. The counter plate is a flat receiving surface, except portions formed as hollows corresponding to the rulings.
The die cutting machine so constructed is able to stamp a sheet of material such as a synthetic resin film, a thin sheet of paper, and a sheet of box board into a desired shape by pressing the cutting blades against the receiving surface of the counter plate by pulling down the cutting die (i.e., from its resting position) after placing the sheet material on the counter plate 60.
As the cutting blade comes into repeated contact with the receiving surface, the counter plate described should be made of a material having an extremely high hardness (i.e., around HRC 500), such as a high hardness stainless steel. However, the use of such hard material results in several disadvantages such as the high cost and time of production. Fabrication of the plate using less hard materials results in less durable cutting parts, especially to the counter plate due to the formation of recessed area as a result of repeated contact with the cutting blades.
Typically, cutting blades are prepared from a band shaped material having an extremely high hardness (i.e., around HRC 500), so that it takes much time to cut the material into pieces having a predetermined length, and to bend each piece into a predetermined shape to form each cutting blade. Furthermore, spring back can occur at the time of bending the cutting blade, and corrective action is usually required to prevent the spring back. Consequently, the fabrication of the cutting blades is a time consuming process.